One thing to consider is if you are recording HD on MiniDV (HDV), and using the default sound recording for it (not an external sound recording device) you will NOT be getting full 48 bit PCM audio – They sacrificed audio quality on the tape to make room for the extra video information – This is not a problem on hard drive or flash.
I will say that editing AVCHD in Sony Vegas Pro 8 on my Core 2 Duo laptop is not a problem – It is, however, on my 2.53 GHz Pentium 4 desktop – You need a fairly current high end machine to edit HD smoothly – There are utilities that will convert AVCHD to MPEG2 for easier editing however.
